OSPF6 Interface Configuration

OSPF6 interfaces are managed at Services > FRR OSPF6 on the Interface tab.

The Interfaces tab contains a list of current OSPF6 interfaces, if any, and controls to manage the entries (e.g. edit, delete). The fa-plus Add button creates a new interface.

OSPF6 must use one or more interfaces to announce itself to neighbors and to receive announcements from neighbors. At least one interface must be configured and active in order to locate neighbors and form an adjacency.

The remaining sections on this page cover the various options available when creating or editing an interface entry.

Interface Options


The interface to use with OSPF6. Entries should be added for interfaces which connect to other routers (neighbors) as well as interfaces containing networks which should be advertised to OSPF6 neighbors.


Text describing the purpose of this interface in OSPF6.

Network Type

Manually configures a specific type of network used on a given interface, rather than letting OSPF6 determine the type automatically. This controls how OSPF6 behaves and how it crafts messages when using an interface.


Broadcast networks, such as typical Ethernet networks, allow multiple routers on a segment and OSPF6 can use broadcast and multicast to send messages to multiple targets at once. OSPF6 assumes that all routers on broadcast networks are directly connected and can communicate without passing through other routers.


A point-to-point network links a single pair of routers. The interface is still capable of broadcast, and OSPF6 will dynamically discover neighbors. With this type of network, OSPF6 disables election of a DR.

Interface is Passive

Configures the specified interface as passive. This prevents the interface from actively participating in OSPF6, while still allowing OSPF6 to operate on networks connected to that interface. This is commonly used for local interfaces without other routers attached. OSPF6 will announce networks attached to passive interfaces as stub links.

Ignore MTU

When present, OSPF6 will ignore the MTU advertised by neighbors and can still achieve a full adjacency when peers do not have matching MTU values.


If two neighbors are stuck in an ExStart state, that is typically from an MTU mismatch. If fixing the MTU mismatch is not viable, set this option on both sides.

OSPF6 Interface Handling


This defines the interface as a member of the given area. If this is left blank, FRR will take the value set in Default Area.

Instance ID

An alternate OSPF6 instance identifier for this interface. Typically omitted or set to 0.


A manual cost value to apply to this interface, rather than allowing automatic cost calculation to take place.

In situations where multiple paths are possible to the same destination, this allows OSPF6 to prefer one path over another when all else is equal.


Router Priority

A priority value, from 0-255, assigned to this router. When determining which router will become the Designated Router (DR), the router with the highest priority is more likely to be elected as the DR.

The default value is 1. The value 0 is special and will prevent this router from being chosen as DR.

Hello Interval

The interval, in seconds from 1-65535, at which this router will send hello messages. This is also known as the HelloInterval timer in OSPF6. Default value is 10. This timer should be set to the same value for all routers.

A lower value will result in faster convergence times, but will consume more resources.

Dead Interval

Time, in seconds from 1-65535, without communication from a neighbor on this interface before considering it dead. This is also known as the RouterDeadInterval timer in OSPF6. Default value is 40. This timer should be set to the same value for all routers.

Retransmit Interval

The interval, in seconds from 1-65535, at which this router will retransmit Link State Request and Database Description messages. This is also known as the RxmtInterval timer in OSPF6. Default value is 5.


When set, enables Bidirectional Forwarding Detection for OSPF6 on this interface.